The invention is directed to a process for the preparation of a cycloalkanol which is carried out in a two stage reaction. In the first reaction stage, a cycloalkene is reacted with sulphuric acid, and in the second reaction stage the resulting adduct which is a cycloalkyl hydrogen sulphate is hydrolyzed to form the cycloalkanol. Although the process according to the invention can be used for preparing any cycloalkanol, especially those with 5-12 carbon atoms in the ring, the invention relates in particular to a process for the preparation of cyclododecanol from cyclododecene.
A process of this type is disclosed in the French Patent Specification 1,407,202. In that process the reaction mixture of the first stage which has present cyclododecyl hydrogen sulphate as the adduct is poured into water or onto ice at a temperature which is not higher than 0.degree. C., while being vigorously stirred. The hydrolysis to cyclodecanol of the cyclododecyl hydrogen sulphate is then completed by heating the resultant reaction mixture to a temperature of about 100.degree. C.
But that process has serious disadvantages including the fact that the amount of water or ice required in the second reaction stage is about 6 kg. per kg. of sulphuric acid used in the first reaction stage. Another disadvantage is that when the reaction mixture of the first reaction stage is added to the water or ice, a large amount of heat is evolved which then must be removed to keep the reaction mixture at 0.degree. C. This cooling is extremely expensive. A further disadvantage is that a large amount of dilute sulphuric acid is obtained as an undesired by-product which must necessarily then be removed from the process.